Eep ...The final adventure awaits! Nothing can stand in the way of Elf Girl and Raven Boy saving the world...Well, almost nothing. Just a sea monster, a dragon, and rivers of molten lava. Not to mention some seriously Creepy Caves. Defeating the Goblin King might be harder than they thought. The sixth laugh-out-loud adventure from BLUE PETER BOOK AWARD-shortlisted Marcus Sedgwick and Pete Williamson.